Electronic devices such as cellular phones and other mobile communication devices may include many built-in electronic devices. Miniaturization of such electronic devices has progressed with miniaturization and “low-profiling” of electronic parts and components of the electronic devices. For example, LC filters may comprise a substrate and a relatively large chip coil or chip capacitor on the substrate.
Some LC filters comprise a ferrite layer with high magnetic permeability inside a ceramic substrate and a coil conductor embedded in the ferrite layer. Ceramic substrates may comprise a pair of insulating layers comprising wiring, and a ferrite layer between the pair of insulating layers. The ferrite layer comprises a flat coil conductor embedded therein. In order to reduce an electrical loss caused by electrical resistance in the wiring and the flat coil conductor, a low-resistance metal such as low-resistance Copper (Cu) or Silver (Ag) may be used for the wiring and the flat coil conductor. Since such a low-resistance metal generally has a relatively low melting point, a glass-ceramic substrate is generally manufactured by simultaneously firing the insulating layers and the ferrite layer.